The group has one VAT number and files one return, so the digital record-keeping requirement attaches to the group as a whole and the consolidated figures must reach HMRC through digital links. That is harder than it sounds, because each member typically keeps its own records in its own system, and the consolidation step is exactly where someone usually opens a spreadsheet and starts typing. Combining member data into the group return has to be digitally linked like everything else. The practical answers are either putting members on a common platform, or accepting a consolidation spreadsheet with proper imports and bridging on top. Groups are one of the few situations where we genuinely recommend bridging, because the consolidation logic is often specific enough that no package handles it cleanly.